For example, rudders or rudder segments are provided in wing and control surfaces for control purposes. Additional flaps are also used for adjusting the profile to aerodynamic conditions, for example in the starting phase, during cruise flight, or even in the landing phase. Both the use of rudder elements and the use of additional flaps serves to change the aerodynamically active profile, i.e., so as to be able to adjust the respective wing and control surfaces to various situations. For example, DE 103 17 258 B4 describes an adjustment mechanism for a variable-shape wing. However, it has been shown that there exists an added demand for further changes in the contour of the wing profile.
Therefore, the object of the present embodiment is to provide an aerodynamic structure that can be adjusted and changed in a variety of ways with regard to the wing profile.
This object is achieved by an aerodynamic structure for a wing or rudder arrangement of an aircraft, an aircraft, a method for adjusting the outer contour of an aerodynamic structure for a wing or rudder arrangement, and the use of an aerodynamic structure in an aircraft according to one of the independent claims. Exemplary embodiments are described in the dependent claims.
According to a first aspect of the embodiment an aerodynamic structure for a wing or rudder arrangement of an aircraft is provided. The aerodynamic structure comprises a support structure and an outer skin. The support structure comprises a fixed spar in the longitudinal direction, which extends from a root area to an outer end area. The support structure comprises several adaptive framework segments in the transverse direction, which each consist of a plurality of strung together triangular compartments that are formed by fixed-length guiding elements and length-adjustable guiding elements. The framework segments are joined to the fixed spar. At least one side of at least a portion of the triangular compartments comprises one of the adjustable guiding elements, so that the shape of the framework segments may be adjusted. The outer skin is held by the framework segments. By adjusting the shape of the frameworks, an outer contour of the aerodynamic structure may be changed at least in the transverse direction.
The advantage to providing the variable framework segments in a transverse direction is that a variety of contour changes are possible, since already the support structure, i.e., the framework segments themselves, are variable in terms of their contour. As a consequence, the wing or rudder arrangement may be adjusted in a variety of ways to different requirement profiles from the inside out, so to speak.
Because the outer contour is adjustable, the aerodynamic drag may be reduced, for example in the case of rudders or also wings. The aerodynamic performance of the wing or rudder may be improved at the same time, for example because slits for modifying the aerodynamically effective contour in the case of additional flaps, etc., are not required due to the changing shape of the support structure. Another advantage to the absent slits is a reduction in noise and decrease in the electromagnetic signature (radar signature) of an aircraft.
The terms “transverse direction” and “longitudinal direction” relate to a wing or rudder arrangement running transverse to the flight direction. For example, the longitudinal direction of an oblong wing as viewed in the attachment direction runs transverse to the flight direction. The transverse direction then runs in the flight direction, for example.
Given wing or rudder arrangements inclined relative to the flight direction, the transverse direction runs inclined in relation to the longitudinal axis of the wing, for example.
Given a wing or rudder arrangement attached at one end to a support structure, e.g., a fuselage structure, the longitudinal direction may also be referred to as the attachment direction, overhang direction or primary direction. The transverse direction then runs transverse to the attachment direction, and may also be referred to as the secondary direction.
In the case of a wing, the root area is the wing root, and the outer end area is the outer wing end.
The fixed-length guide elements are also referred to as fixed guide elements or bar elements. For example, the fixed guide elements are movably mounted, e.g., at node points designed as hinge points.
The adjustable-length guide elements are also referred to as actuating drives, actuating elements or actuators.
The support structure is formed by the spar and the framework segments attached thereto. The support structure therefore forms a stable inner structure of the aerodynamic structure, for example of a wing or a rudder.
“Aerodynamic structure” refers to the constituent of a wing or rudder arrangement that produces the aerodynamic effect during aircraft operation, e.g., generates an upward (or downward) force on a wing, or generates a torque on a rudder to change the direction of the aircraft. The aerodynamic structure may also be referred to as a wing or rudder structure. The term “aerodynamic structure” is used in conjunction with the present embodiment to denote the constituents shared in common by a wing and rudder arrangement. For example, wing and rudder arrangements comprise an outer surface exposed to the air flow, which is also referred to as the outer skin. This surface produces the desired aerodynamic effect, e.g., due to its contour or shape and its inclination, i.e., because of its cross section exposed to the air flow. Wing and rudder arrangements also comprise a support structure, so as to hold the surface exposed to the air flow, and introduce the generated forces into the structure of the aircraft.
For example, the aircraft is an airplane; e.g., the aerodynamic structure is a wing surface of a supporting framework or a control surface of a tail unit. The “wing surface” is also referred to as a wing arrangement. In another example, the wing surface is an (essential) constituent of the wing arrangement. The “control surface” is also referred to as a rudder arrangement. In another example, the control surface is an (essential) constituent of the rudder arrangement. The adaptive framework segments provide a variably shaped aerodynamic structure.
In an example, the framework segments are connected to the fixed spar transversely to its longitudinal direction in such a way as to provide triangular compartments on both sides of the spar.
For example, the spar is designed so as to be integrated in a field of the framework segment, so that the framework segment extends to both sides of the spar, e.g., the framework segment for a wing designed transverse to the flight direction extends with a spar running transverse to the flight direction toward the front and back in the flight direction.
For example, the wing profile may be adjusted over a majority of the cross section by the variable framework structure.
For example, the framework segment for a wing is arranged in a central wing area in the longitudinal direction of the wing, i.e., between the root area and wing tip, so that the profile of the wing may be varied at least in the central area. One example provides that approx. two thirds of the wing length or rudder extension be designed as a structure with an adjustable cross section.
In another example, this is provided for a rudder arrangement.
Another example provides that the framework segment consist of two sub-segments, and that a respective sub-segment be connected on one side of the spar, and the other sub-segment on the other side of the spar.
In an example, the spar forms a fixed structural element of a wing or rudder arrangement, and the adjoining framework segments enable an adjustment of the outer contour.
For example, the framework segments are connected to the spar in a central area, and are divided by the spar into two areas, e.g., into a front and rear area. Both the front and rear area are adjustable in design.
In an example, the spar forms a longitudinal beam, to which several framework segments are sequentially attached as transverse ribs.
For example, the transverse ribs are ribs that run transverse to the spar.
In an example, several framework segments are arranged parallel to each other, and run parallel to the flight direction.
An example provides that fixed guide elements be continuously strung together in the direction of the framework segment.
This provides a basic support structure running in the transverse direction of the wing for introducing the forces into the fixed spar, which may be variably adjusted given the configuration of the triangular fields.
In an example, the adjustable guide elements in the triangular compartments are arranged in such a way that each triangular compartment comprises an adjustable guide element on the side facing the outside.
This enables an adjustable profile over the entire length of the cross section.
For example, the framework segments comprise adjustable guide elements on their two longitudinal sides, i.e., strung together on the upper and lower belt. The stringing together is only interrupted by the spar, for example.
In an example, the aerodynamic structure forms a front edge on a longitudinal edge. The end area of the framework segments that faces the front edge is designed with a fixed, triangular compartment. This provides additional stability in the area of the front edge. For example, the front edge forms an edge area that is exposed to inflowing air during operation.
In an example, the fixed spar comprises a triangular cross section, and has three longitudinal edges. The triangular cross section is integrated into the framework segments. It is provided that the fixed or adjustable guide elements be attached to the three longitudinal edges.
This ensures a sufficient load-bearing capacity in the longitudinal direction on the one hand, and the structure of the adaptive framework segments is only limited in one area on the other, for example when one side of the triangular spar faces up or down, so that a field cannot be adjusted within the framework segment. The triangular cross section allows the spar to be integrated into the structure of the framework segments, thus replacing the framework segments with the spar itself in this area, i.e., in the area of the spar. This economizes on material, which is important especially in terms of weight.
In an example, the outer skin may be shaped, and is attached to the framework segments at least partially via hold points by retaining elements. At least a portion of the retaining elements is designed as adaptive mounts, with which the location of the hold points in relation to the framework segments may be varied.
The retaining elements are also referred to as secondary guide elements, and the adaptive mounts as secondary, adjustable-length guide elements. The guide elements of the framework segments may be referred to as primary guide elements, i.e., primary fixed-length guide elements, and primary adjustable-length guide elements.
For example, the front edge and lateral surfaces of the outer skin are attached to the framework segments by retaining elements. On the rear edge, the outer skin may be attached directly to the end areas of the framework segments.
For example, the hold points are designed as a secondary wing assembly, e.g., as a girder grid with support brackets running transverse to the framework segments. The framework segments together with the spar form the primary wing assembly.
Adaptive mounts provide an additional adjustability, which in particular also enables a finer adjustment of the outer contour.
In an example, the adaptive mounts are adjustable-length hold members, with which the distance between the hold points and framework segments may be adjusted.
In another example, the adaptive mounts are alternatively or additionally designed as pivoting arms, whose pivoting degree relative to the framework segments may be adjusted.
In an example, the outer skin is designed as a single piece.
Giving the outer shell a continuous design improves the aerodynamic performance of the aerodynamic structure. By avoiding in particular slits, the noise generated on the wings during flight operations is also reduced.
For example, the outer skin is flexible transverse to the surface. In another example, the outer skin is designed so that it may expand in the direction of the surface, e.g., an expandable material or expandable structure is provided for the outer skin, for example honeycombs and hybrid composites filled with elastic plastics.
An example provides that changing the profile be controlled in such a way as to prevent any change in length from arising in the surface of the outer skin. It is provided for this example that the outer skin be pliable within a certain range, but need not be expansible.
According to the embodiment an aircraft is provided, which comprises a fuselage structure, a wing assembly with at least one wing surface, and a tail unit with at least one control surface. The wing assembly and tail unit are held on the fuselage structure. At least one wing surface and/or one control surface is designed with an aerodynamic structure according to one of the preceding examples.
For example, the wing assembly encompasses one or more wings. For example, the tail unit encompasses an elevator, a fin and/or an aileron.
Also provided are combinations thereof, e.g., tailerons or V-tail units. Tailerons are elevators provided on the tail of an airplane, and in which the actual functions of an aileron are enhanced or even entirely replaced by independently actuating the two rudder halves.
According to the embodiment a method for adjusting an outer contour of an aerodynamic structure for a wing or rudder arrangement is provided, which comprises the following steps: a) Providing an aerodynamic structure for a wing or rudder arrangement of an aircraft. The aerodynamic structure comprises a support structure and an outer skin. The support structure comprises a fixed spar in the longitudinal direction, which extends from a root area to an outer end area. The support structure comprises several adaptive framework segments in the transverse direction, which each consist of a plurality of strung together triangular compartments, which are formed by fixed-length guide elements and adjustable-length guide elements. The framework segments are connected to the fixed spar. The outer skin is attached to the framework segments. At least one side of at least a portion of the triangular compartments comprises one of the adjustable guide elements, so that the framework segments have an adjustable shape. Adjusting the shape of the framework segments makes it possible to vary the outer contour of the aerodynamic structure, at least in the transverse direction, b) Adjusting the adjustable-length guide elements, and c) Changing the outer contour of the aerodynamic structure at least in the transverse direction.
The embodiment also provides for the use of an aerodynamic structure according to one of the preceding examples in an aircraft.
An aspect of the embodiment provides that an aerodynamic structure, for example a wing, be designed with an adjustable support structure. The support structure is adjusted by designing carriers running in the transverse direction as framework structures, in which the fields are triangular in design, so that an actuator may be provided on one side of the triangular fields, in order to generate a displacement or change in shape of the framework structure via a corresponding change in length of the actuator. Since the outer skin is attached to the framework structures, changing the inner support structure also causes a change to the outer contour. In addition, the aerodynamic structure may be altered by changing the length of the actuators between the framework structure and outer skin.
It is noted that the features in the exemplary embodiments and aspects of the devices also apply to embodiments of the method and use of the device and vice versa. In addition, those features may be freely combined with each other even if doing so is not explicitly mentioned, wherein synergistic effects may arise that go beyond the sum total of different features.